In modern society, mobile phones become essential communication devices because they are portable. In some circumstances, however, the mobile phone is not suitable to be hand-held. For example, in the case of driving while using the mobile phone, the likelihood of the traffic accident is increased because only one hand is available for driving. In addition, the user may feel tired and inconvenient in a case of using the hand-held mobile phone for a long time period.
For a purpose of increasing convenience of using mobile phones, many mobile phone accessories such as mobile phone earphone devices, hands-free headsets and the like were developed.
The conventional mobile phone earphone device comprises an earphone and a microphone. The earphone device is plugged in a signal receiving socket of a mobile phone via a wire. When answering a call, the user can hear the caller via the earphone and dialogize with the caller via the microphone.
Although this wired earphone device is applicable when the mobile phone is not suitable to be hand-held, the wire connection between the earphone device and the mobile phone limits the mobility of the user.
In order to expand flexibility of using the hands-free mobile phone and avoid inconvenience of wire linkage, a bluetooth earphone was developed. As known, the bluetooth technology is a wireless transmission technology generally used in localized area, and will not be described in detail herein. The bluetooth earphone has therein a signal processing circuit, which cooperates with a mobile phone having a bluetooth chip to answer calls via the earphone device without the requirement of an electrical cable between the earphone and the mobile phone.
Such a wireless earphone device is not satisfactory because the user usually feels uncomfortable when a weighty or bulky wireless earphone is worn on the user's ear. In particular, it is inconvenient for the user who wears glasses to wear the wireless earphone because the glasses frame may interfere with the wireless earphone.
Accordingly, the above-described prior art method is not a perfect design and has still many disadvantages to be solved.